Advance directives, substituted judgment, and the best-interest standard all have limitations that constrain their usefulness in making medical decisions for patients who cannot choose for themselves.
Our ability to infer mental states from fMRI scans is still rudimentary, but the time may be approaching when neuroimaging can be used to indicate witnesses’ reliability in court proceedings.
Advance directives do not always resolve questions about the best care for patients who no longer have decision-making capacity; physicians and patient surrogates can take alternative approaches to arrive at the best care decision.